linux-kernel - Re: [patch V4 part 2 06/18] x86/entry: Move irq flags tracing to prepare_exit_to

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CALCETrWAWHByoifmzcXpMpYgcABkRNNM3ihsJ1pe5jzaayvkHA@mail.gmail.com>
Date:   Fri, 8 May 2020 16:57:50 -0700
From:   Andy Lutomirski <luto@...nel.org>
To:     Thomas Gleixner <tglx@...utronix.de>
Cc:     LKML <linux-kernel@...r.kernel.org>, X86 ML <x86@...nel.org>,
        "Paul E. McKenney" <paulmck@...nel.org>,
        Andy Lutomirski <luto@...nel.org>,
        Alexandre Chartre <alexandre.chartre@...cle.com>,
        Frederic Weisbecker <frederic@...nel.org>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <sean.j.christopherson@...el.com>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Petr Mladek <pmladek@...e.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Joel Fernandes <joel@...lfernandes.org>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Juergen Gross <jgross@...e.com>,
        Brian Gerst <brgerst@...il.com>,
        Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
        Josh Poimboeuf <jpoimboe@...hat.com>,
        Will Deacon <will@...nel.org>
Subject: Re: [patch V4 part 2 06/18] x86/entry: Move irq flags tracing to prepare_exit_to_usermode()

On Tue, May 5, 2020 at 7:14 AM Thomas Gleixner <tglx@...utronix.de> wrote:
>
> This is another step towards more C-code and less convoluted ASM.
>
> Similar to the entry path, invoke the tracer before context tracking which
> might turn off RCU and invoke lockdep as the last step before going back to
> user space. Annotate the code sections in exit_to_user_mode() accordingly
> so objtool won't complain about the tracer invocation.

Acked-by: Andy Lutomirski <luto@...nel.org>

Note to self: the nmi code needs to be reworked to go through
prepare_exit_to_usermode(), too.  I'll do this once this whole pile
lands.